New report on European bat population trends

Bat populations are generally understood to have undergone significant declines throughout Europe, particularly during the second half of the 20th century. The declines have been variously attributed to the intensification of agriculture, persecution, destruction of roosts, and habitat loss/fragmentation. Other impacts, such as increasing use of toxic chemicals used in timber treatment, have also been implicated.

However, according to a new report that has just been published by the European Environment Agency (EEA), bat numbers across Europe are recovering after years of decline. This report is entitled ‘European bat population trends – A prototype biodiversity indicator’. A link to download this report is provided below.

Recovering numbers hailed as conservation success but many species remain endangered

New report on European bat population trends

This study is the largest and most comprehensive study of European bat population trends ever undertaken. A total of 16 bat species (of the 45 bat species that occur) in nine countries were assessed, and it was found that the total number increased by 43% in the period between 1993 and 2011, “with a relatively stable trend since 2003“. During this work, surveyors assessed bats hibernating at 6,000 sites across Europe. Most of the species studied were found to to be increasing or were stable in number. Nine of the species studied showed a positive population trend across the study area.The Greater Horseshoe bat Rhinolophus ferrumequinum doubled in numbers, while the Lesser Horseshoe bat Rhinolophus hipposiderosincreased by 77%. Other good news from this study was that the population of the Natterer’s bat Myotis nattereri increased by 83%.

Only the grey long-eared bat Plecotus austriacus showed a significant decline. The most recent figures from the UK National Bat Monitoring Programme also how that this is also the species of most concern in the UK. For example the UK population of Grey Long-eared bats numbers fewer than 1,000 individuals, according to the Bat Conservation trust (see Daily Mail, 2013). No trend could be determined for either Bechstein’s bat Myotis bechsteinii or Northern bat Eptesicus nilssonii. Grey Long-eared bat, Bechstein’s bat, and the Northern bat do not occur in Ireland.

Referring to the publication of the EEA report Dr Karen Haysom of the Bat Conservation Trust, as quoted in Guardian newspaper, said “This report is important for wildlife, because understanding population change is an essential step in planning and implementing effective conservation“.

The report notes that the potential impact of wind turbines on migratory species is not fully understood.

Potential impact of wind turbines on migratory species is mentioned in EEA report

It is thought that conservation measures, such as bat protection legislation and better habitat management, have contributed significantly to reversing the decline. Targeted conservation measures and widespread awareness-raising, particularly under the EUROBATS agreement, may have provided significant benefits to bat populations according to the report. However the report says that bats should still be considered vulnerable and it is considered that current populations are smaller than those that occurred historically. The report also notes that there are a number of emerging threats to bat populations where more information is needed. The potential impact of wind turbines on migratory species is mentioned in this regard.

According to National Geographic, Dr Haysom said that this “study provides a cautiously encouraging message” and “it shows that positive conservation stories are possible“.According to Phys.org Hams Bruyninckx, the executive director of the EEA, said “It is extremely encouraging to see bat populations increasing after massive historic declines“. The EEA said many species and countries were not represented; for example Ireland was not included in this study. Moreover, only 16 bat species out of the 45 bat species that occur in Europe were assessed.

Bat survey and assessment services

We have several bat experts on our staff who are licensed for all types of bat surveys. We have a range of bat survey equipment in-house, including specialist static detectors (i.e. Anabat systems) that can be left in place to monitor the use of an area by bats over extended periods. This approach is particularly useful at proposed wind farm sites. We can advise on the best course of action to take for any project that may affect bats. Early consultation is always important since bat use of sites tends to be seasonal, and appropriate planning of survey times is essential. ECOFACT is Ireland’s leading independent provider of bat surveys and bat impact assessments. Also refer to the bat surveys section of our main website. If you require any further information on bats or bat surveys, please do not hesitate to contact us at +353 61 419477.

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Published by Dr. Will O'Connor

Dr. Will O’Connor is a Senior Ecologist who has over 25 year’s professional experience. He is a graduate of the University of Wales, Cardiff, and the National University of Ireland, Galway. He is a Fellow of the Royal Society of Biology, and a full member of both the Chartered Institute of Ecology and Environmental Management and the Institute of Fisheries Management. He is a Chartered Environmentalist and a Chartered Biologist.
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